Improvement in solutions for chemical telegraph-paper



UNITED STATES PATENT QFFICE.

THOMAS A. EDISON, OF NEWARK, NEW JERSEY, ASSIGNOR TO HIMSELF AND GEORGE HARRINGTON, OF WASHINGTON, D. U.

IMPROVEMENT IN SOLUTIONS FOR CHEMICAL TELEGRAPH-PAPER.

Specification forming part of Letters Patent No. 160,580., dated March 9, 1875; application filed June 1, 1874.

To all whom it may concern:-

Be it known that I, THOMAS A. EDIsoN, of Newark, in the county of Essex and State of New Jersey, have invented an Improvement in Solutions for Chemical Telegraphic Paper, of which the following is a correct description:

I make use of about five pennyweights of aurichloridc of sodium (double chloride of gold and sodium) to a pint of water, and about an ounce of nitrate of ammonia.

A small amount of bichloride of mercury increases the sensitiveness of the paper. This, however, may be omitted, and, in place of hi trate of ammonia, any other salt may be employed having a corresponding reaction with the aurichloride of sodium.

THOMAS A. EDISON. \Vituesses:

GEO. T. PINOKNEY, CHAS. H. SMlTH. 

